Counterholder device for an apparatus for removing knockout parts from a workpiece sheet or the like, and apparatus having a counterholder device

ABSTRACT

Counterholder device ( 10; 10   a  to  10   f ) for an apparatus ( 100 ) for removing knockout parts ( 1; 1   f ) from a workpiece sheet ( 2 ) or the like, including a basic body ( 11 ) which can be arranged in a cutout ( 104 ) of a die ( 105 ) of the apparatus ( 100 ) and which is connected to a tongue-like portion ( 12;   12   c ) which projects into the cutout ( 104 ) of the die ( 105 ), wherein the shape of the cutout ( 104 ) is adapted to the shape of the knockout part ( 1; 1   f ) and wherein the tongue-like portion ( 12; 12   c ) interacts with a knockout element ( 103;   103   d ), which penetrates into the cutout ( 104 ) and in so doing is arranged at a distance from the tongue-like portion ( 12; 12   c ), and with an edge portion of the knockout part ( 1; 1   f ), wherein at least the tongue-like portion ( 12; 12   c ) is rigidly formed in such a way that it is arranged in a fixed position when interacting with the knockout part ( 1; 1   f ) and the knockout element ( 103; 103   d ).

BACKGROUND OF THE INVENTION

The invention relates to a counterholder device for an apparatus forremoving knockout parts from a workpiece sheet or the like.

Such a counterholder device is known from DE 697 01 218 T2. The knowncounterholder device is characterized by a tongue-like portion whichprojects into a cavity for a knockout part of a die, with regions of theknockout part resting on the ends of the tongue-like portions. Duringthe knockout process, a knockout member moves vertically from top tobottom and thus comes into contact with the knockout part. In so doing,the knockout part is pressed at its edge regions against the tongue-likeportions of the counterholder device. During the further downwardmovement of the knockout member, the tongue-like portion of thecounterholder device moves downward together with the knockout memberand with the interposition of the knockout part. At the same time, anelastic deformation of the tongue-like portion of the counterholderdevice takes place. During the further downward movement of the knockoutpart, the tongue-like portions are overstretched until (with theknockout part already separated out) they snap over the knockout partsand assume their original position again. It is thus ensured that,during the subsequent upward movement of the knockout member, theknockout part possibly adhering to the knockout member is stripped fromthe knockout member at the tongue-like portion of the counterholderdevice. The design and dimensioning of the known counterholder devicemust be designed as a function of the respective knockout part.Moreover, owing to the required flexibility or elasticity of thetongue-like portion, the counterholder device is usually produced fromcompression-molded material whose durability or number of cycles islimited.

Furthermore, in the 1970s, the Applicant developed the so-called “PowerStripping Dyn Stiftsystem”. Here, the die is provided with stud-likeprojections which serve as abutments when pressing down the knockoutparts. Owing to the resistance of the stud-like projections, thenecessary nonpositive engagement for a relatively reliable knockoutoperation results between the knockout part and the pins responsible forthe downward movement of the knockout part. A disadvantage here,however, is that the stud-like protuberances on the die tend to wear asa result of the constant friction between the knockout parts and saidprotuberances. Consequently, it is relatively difficult to ensure thefunctional reliability of the knockout process over a prolonged period.

SUMMARY OF THE INVENTION

Starting from the prior art represented, the object on which theinvention is based is to develop a counterholder device for an apparatusfor removing knockout parts from a workpiece sheet or the like suchthat, together with a high process reliability, a very long service lifeof the counterholder device is made possible. This object is achieved inthe case of a counterholder device as disclosed herein. The idea behindthe invention is to reduce the wear of the counterholder device by meansof rigid, tongue-like portions.

Advantageous developments of the counterholder device according to theinvention are also specified herein. Falling within the scope of theinvention are all combinations of at least two features disclosed in theclaims, the description and/or the figures.

With particular preference, it is provided that the basic body and thetongue-like portion consist of hard material, in particular of metal.Owing to the metal design, the counterholder devices have a particularlyhigh durability or service life and, moreover, can be handledparticularly easily, for example can be fitted into the correspondingrecesses of the die.

The counterholder devices can be produced particularly economically andcost-effectively if the basic body and the tongue-like portion areconnected to one another in one piece and are formed as a stamped/bentpart.

In an alternative embodiment, it is also possible that the basic bodyand the tongue-like portion are connected to one another in one pieceand are formed as a cast part or milled part.

For simple fastening of the counterholder device in the die, it isprovided that the basic body is accommodated in the recess with a formand force fit, and that the basic body has a conical shape. Given acorrespondingly accurately produced cavity, the conical shape moreovermakes possible or ensures an exact height positioning of thecounterholder device in the die.

In this case, it is also particularly provided that the upper side ofthe basic body and of the tongue-like portion terminates at leastapproximately flush with the upper side of the die. This also reliablyprevents a catching of parts of the blanks during their transport abovethe die.

Furthermore, it is particularly preferred if the tongue-like portion hasa structured shape on the side facing away from the basic body. Thismakes it possible in an advantageous manner to ensure a high operationalreliability of the apparatus.

It is particularly preferred here if the structured shape is formed as atoothing. By means of such toothings, in particular by means of finetoothings, it becomes possible to adapt the counterholder device to therespective waste contours to be knocked out.

The invention also comprises an apparatus for removing knockout partsfrom a workpiece or the like, having a counterholder device according tothe invention. Such an apparatus has the advantage of a particularlyhigh operational reliability and service life.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages, features and details of the invention will emergefrom the following description of preferred exemplary embodiments andwith reference to the drawings, in which:

FIG. 1 shows a longitudinal section through an apparatus for removingknockout parts from a workpiece sheet or the like using counterholderdevices according to the invention,

FIG. 2 shows a plan view of the die of the apparatus according to FIG.1,

FIG. 3 and FIG. 4 show exemplary embodiments of counterholder devicesaccording to the invention, in each case in a perspective view, and

FIG. 5 to FIG. 10 show partially simplified plan views of counterholderdevices according to the invention in order to illustrate the differentfine toothings in the region of the tongue-like portions.

DETAILED DESCRIPTION

Like parts or parts having the same function are provided with identicalreference numbers in the figures.

FIGS. 1 and 2 depict an apparatus 100 for removing knockout parts 1 froma workpiece sheet 2 or the like.

The workpiece sheet 2 is in particular a cardboard or a corrugated boardand the knockout part 1 is a part which is connected via webs or thelike to the remaining workpiece sheet 2 and which is intended to bedetached from the workpiece sheet 2 by means of the apparatus 100. Suchan operation is also referred to as knocking out.

The apparatus 100 comprises a lower part 101 which is arranged in afixed position, preferably consisting of multi-glued plywood, and anupper part 102 which is arranged movably up and down with respect to thelower part 101 and which likewise preferably consists of multi-gluedplywood. Arranged on the underside of the upper part 102 is preferably aplurality of knockout elements 103 which, in the exemplary embodimentrepresented, are formed as bent sheet-metal parts or else as steel pins.The knockout elements 103 can in particular also be designed inaccordance with EP 1 068 053 B1 of the Applicant and have, for example,additional pushing teeth for the targeted movement of the knockout part1.

As can best be seen from FIG. 2, the lower part 101, which is alsodesignated as “knockout board”, has a cutout 104 which is rectangular inthe exemplary embodiment and whose outline is adapted to the shape orsize of the knockout part 1 in such a way that the knockout part 1 issomewhat smaller than the cavity 104 and is enclosed at a distancethereby. Moreover, for the sake of better clarity, FIG. 2 only shows theknockout part 1 but not the remaining workpiece sheet 2. Owing to thedesign of the cavity 104 in the lower part 101, the lower part 101 actsas a die 105.

The cavity 104 is equipped with additional recesses 107 in order toaccommodate counterholder devices 10 according to the invention.Moreover, like the cavity 104, the recesses 107 are produced or formedin particular by means of laser beam cutting devices. The recess 107 hasa first region 108 which is approximately rectangular in plan view andwhich is connected to the cavity 104 via a second region 109 which isapproximately trapezoidal in the exemplary embodiment. Moreover, boththe cavity 104 and the recess 107 are formed over the entire height orthickness of the lower part 101.

The apparatus 100 according to FIGS. 1 and 2 has four counterholderdevices 10 according to the invention which are each arranged in pairs,opposite one another in the exemplary embodiment, on the twolongitudinal sides of the cavity 104.

As can best be seen from FIGS. 3 and 4, the counterholder device 10 hasa block-shaped basic body 11 which is preferably connected in one pieceto a tongue-like portion 12. While the counterholder device 10 aaccording to FIG. 3 is produced from a sheet-metal part by astamping/bending process, the counterholder device 10 b according toFIG. 4 has a solid basic body 11 on which the portion 12 is integrallyformed. In this case, the counterholder device 10 b can be formed forexample as a milled part or else as a cast part.

The basic body 11 is conically formed such that, when inserted orfastened in the first region 108 of the recess 107, it is securelyaccommodated in the recess 107 by clamping or pressing, while the upperside of the basic body 11 and of the portion 12 preferably terminatesflush with the upper side of the lower part 101.

What is essential is that the counterholder devices 10, 10 a or 10 bconsist of hard material, in particular of metal, and that thetongue-like portion 12 is rigidly formed or arranged in a directionparallel to the direction of movement of the upper part 102 of theapparatus 100.

The end portions or end regions 14 of the tongue-like portions 12 whichface away from the basic body 11 preferably have a fine toothing 15.Whereas in the exemplary embodiment represented in FIG. 5 the finetoothing 15 a of the counterholder device 10 a is formed over the entirewidth of the tongue-like portion 12, the tongue-like portion 12 c of thecounterholder device 10 c of FIG. 6 has a widened head region 17 whichlikewise has a fine toothing 15 c over its entire width. The end region14 d of the counterholder device 10 d of FIG. 7 has a semicircular orconcave cutout 18 which interacts with a pin-like knockout element 103d. By contrast, the counterholder device 10 e according to FIG. 8 has aconvexly formed end region 14 e with a fine toothing 15 e. Thecounterholder device 10 f according to FIGS. 9 and 10 is intended inparticular for small, round knockout parts 1 f. For this purpose, thecounterholder device 10 f has a star-shaped fine toothing 15 f withinternal points 19. Here, according to FIG. 10, the knockout part 1 frests on the points 19 which are concealed in said figure. The knockoutelement preferably used for the counterholder device 10 f is across-sectionally round pin which, during its downward movement,penetrates into the opening of the counterholder device 10 f which isbounded by the points 19.

The particular shape of the fine toothings 15 or the dimensioning of thetongue-like portions 12 should in particular be adapted to theparticular application, i.e. in particular to the shape of the knockoutpart 1 and the material used.

The mode of operation of the apparatus 100 in conjunction with thecounterholder elements 10 according to the invention is as follows: assoon as the workpiece sheet 2 is positioned with its knockout part 1 inthe region of the cavity 104 of the apparatus 100, the upper part 102begins to move downward, and the knockout elements 103, which arearranged at a distance from the counterholder elements 10 in thedirection of movement, come into operative connection with the upperside of the knockout part 1. In so doing, the knockout elements 103press the knockout part 1 into the cavity 104, and the edge regions ofthe knockout part 1 come into operative connection with the tongue-likeportions 12, in particular with the fine toothings 15 of thecounterholder elements 10. This results in a frictional engagementbetween the knockout part 1, the counterholder devices 10 and theknockout elements 103.

As the knockout part 1 is pressed down further into the cavity 104, the(web-like) connections between the knockout part 1 and the workpiecesheet 2 break, with the result that the knockout part 1 is pressed intothe cavity 104 with further deformation. It is essential here that thetongue-like portions 12 of the counterholder devices 10 remain at leastsubstantially rigid at their location, i.e. are not pressed into thecavity 104. As the knockout part 1 is pressed into the cavity 104, theknockout part 1 is here deformed until its edge regions overcome the endregions 14 of the tongue-like portions 12 of the counterholder devices10, such that the knockout part 1 passes into a waste container or thelike situated below the lower part 101. During the subsequent upwardmovement of the upper part 102 of the apparatus 100, it is ensured bythe rigid counterholder devices 10 that a knockout part 1 possiblyadhering to the knockout elements 103 bears against the underside of thecounterholder devices 10 and is prevented by these from making a furtherupward movement or is stripped from the knockout elements 103. Thisensures a reliable separation of the already separated-out knockout part1 from the knockout elements 103.

The counterholder devices 10 described so far can be adapted or modifiedin numerous ways without departing from the idea of the invention. Inparticular, the shape and the choice of the material of thecounterholder device is not limited to the embodiments which have beenillustrated or described. Furthermore, it can also be provided that thecounterholder devices 10 have, in particular for the use for relativelylarge, round knockout parts 1, 1 f, a receptacle on both sides, i.e.arranged opposite one another.

1. Counterholder device (10; 10 a to 10 f) for an apparatus (100) forremoving knockout parts (1; 1 f) from a workpiece sheet (2) or the like,comprising a basic body (11) which can be arranged in a cutout (104) ofa die (105) of the apparatus (100) and which is connected to atongue-like portion (12; 12 c) which projects into the cutout (104) ofthe die (105), wherein the shape of the cutout (104) is adapted to theshape of the knockout part (1; 1 f) and wherein the tongue-like portion(12; 12 c) interacts with a knockout element (103; 103 d), whichpenetrates into the cutout (104) and in so doing is arranged at adistance from the tongue-like portion (12; 12 c), and with an edgeportion of the knockout part (1; 1 f), wherein at least the tongue-likeportion (12; 12 c) is rigidly formed in such a way that it is arrangedin a fixed position when interacting with the knockout part (1; 1 f) andthe knockout element (103; 103 d).
 2. Counterholder device according toclaim 1, wherein the basic body (11) and the tongue-like portion (12; 12c) consist of hard material.
 3. Counterholder device according to claim2, wherein the basic body (11) and the tongue-like portion (12; 12 c)are connected to one another in one piece and are formed as astamped/bent part.
 4. Counterholder device according to claim 2, whereinthe basic body (11) and the tongue-like portion (12; 12 c) are connectedto one another in one piece and are formed as a cast part or milledpart.
 5. Counterholder device according to claim 1, wherein the basicbody (11) is accommodated in the cutout (104) with a form and force fit,and wherein the basic body (11) has a conical shape.
 6. Counterholderdevice according to claim 1, wherein the upper side of the basic body(11) and of the tongue-like portion (12; 12 c) terminates at leastapproximately flush with the upper side of the die (105). 7.Counterholder device according to claim 1, wherein the tongue-likeportion (12; 12 c) has a structured shape on the side facing away fromthe basic body (11).
 8. Counterholder device according to claim 7,wherein the structured shape is formed as a toothing (15; 15 a; 15 c; 15e; 15 f).
 9. Apparatus (100) for removing knockout parts (1) from aworkpiece sheet (2), having a counterholder device (10; 10 a to 10 e)according to claim
 1. 10. Counterholder device according to claim 2,wherein the basic body (11) and the tongue-like portion (12; 12 c)consist of metal.